Using your fingers (thumb and forefinger) is the best hackle guard you can every buy. And the price is right as well. I know, I know, until you get the hang of it, you well poke some holes in your fingers or tie some hackle down; but the end result of learning how to hold the hackle back out of the way with your fingers is worth the trouble to learn how.
If you absolutely must have a hackle guard, get yourself a bodkin that has a small, wire loop on one end. The loop goes over the hook eye and is a very functional and easy to use hackle guard. And bodkins with this loop on the end are not expensive.